This is actually relatively complicated to achieve, since it involves
overriding GHC on e.g. aarch64-darwin, so the FAQ entry seems warranted.
It's also a good exercise to me, since it demonstrates some problems
with the overriding infrastructure, i.e. that it has a tendency to
inherit the pkgs fixpoint from prev. An example of this problem is
https://github.com/NixOS/nixpkgs/issues/235960, but it has different
manifestations as well. Awareness of this will also help writing the
other sections on overriding.
How complicated it is, seems to be further incentive to go ahead with
https://github.com/NixOS/nixpkgs/pull/239548 as well.
8088e14e12